When reading a node from a federated filesystem connector using the JCR API it throws a NullPointerException. This node represents a file and it could be read normally by the graph api.

– test method to be used inside the docs/gettingstarted/repository source –

@Test
public void shouldAccessFileSystemByFederatedJcr()
throws Exception

{ JcrConfiguration configuration = new JcrConfiguration(); URL url = Thread .currentThread() .getContextClassLoader() .getResource( "config/repository-federated-with-filesystem-connector-config.xml"); assertNotNull(url); configuration.loadFrom(url); JcrEngine engine = configuration.build(); engine.start(); org.jboss.dna.graph.Node nodeFromGraph = engine.getGraph("Vehicles").getNodeAt("/Vehicles/FileSystem/FileThatExists"); assertThat(nodeFromGraph, is(notNullValue())); Session session = engine.getRepository("Vehicles").login(); Node nodeFromJcr = session.getRootNode().getNode("Vehicles/FileSystem/FileThatExists"); // here I got a NPE assertThat(nodeFromJcr, is(notNullValue())); engine.shutdown(); }

– configuration file to be used on this test –

<?xml version="1.0" encoding="UTF-8"?>
<!--
~ JBoss DNA (http://www.jboss.org/dna)
~
~ See the COPYRIGHT.txt file distributed with this work for information
~ regarding copyright ownership. Some portions may be licensed
~ to Red Hat, Inc. under one or more contributor license agreements.
~ See the AUTHORS.txt file in the distribution for a full listing of
~ individual contributors.
~
~ JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA
~ is licensed to you under the terms of the GNU Lesser General Public License as
~ published by the Free Software Foundation; either version 2.1 of
~ the License, or (at your option) any later version.
~
~ JBoss DNA is distributed in the hope that it will be useful,
~ but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
~ or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
~ for more details.
~
~ You should have received a copy of the GNU Lesser General Public License
~ along with this distribution; if not, write to:
~ Free Software Foundation, Inc.
~ 51 Franklin Street, Fifth Floor
~ Boston, MA 02110-1301 USA
-->
<configuration xmlns:dna="http://www.jboss.org/dna/1.0" xmlns:jcr="http://www.jcp.org/jcr/1.0">
<!--
Define the sources for the content. These sources are directly accessible using the DNA-specific Graph API.
In fact, this is how the DNA JCR implementation works. You can think of these as being similar to
JDBC DataSource objects, except that they expose graph content via the Graph API instead of records via SQL or JDBC.
-->
<dna:sources jcr:primaryType="nt:unstructured">
<!--
The 'Cars' repository is an in-memory source with a single default workspace (though others could be created, too).
-->
<dna:source jcr:name="Cars" dna:classname="org.jboss.dna.graph.connector.inmemory.InMemoryRepositorySource" dna:retryLimit="3" dna:defaultWorkspaceName="workspace1"/>

<dna:source jcr:name="FileSystem" dna:classname="org.jboss.dna.connector.filesystem.FileSystemSource">
<creatingWorkspacesAllowed>false</creatingWorkspacesAllowed>
<directoryForDefaultWorkspace>/tmp</directoryForDefaultWorkspace>
</dna:source>
<!--
The 'Aircraft' repository is also an in-memory source with a single default workspace.
By defining a default workspace, the clients using the Graph API will by default use that workspace,
but can easily say to use other workspaces (or create, clone, or destroy workspaces).
-->
<dna:source jcr:name="Aircraft" dna:classname="org.jboss.dna.graph.connector.inmemory.InMemoryRepositorySource">
<!-- Define the name of the workspace used by default. Optional, but convenient.
-->
<defaultWorkspaceName>workspace</defaultWorkspaceName>
</dna:source>
<!--
The 'Vehicles' repository is a federated source that owns none of its own content, but instead
projects (in this case) all of the content from the 'Cars' source as if it appears
under '/Vehicles/Cars', while all the 'Aircraft' content appears under '/Vehicles/Aircraft'.
-->
<dna:source jcr:name="Vehicles">
<dna:classname>org.jboss.dna.graph.connector.federation.FederatedRepositorySource</dna:classname>
<dna:workspaces>
<!--
Unlike some other repository sources, federated sources have to define all of their workspaces,
including how and where the content is projected. So, we only need a single workspace,
but we could actually define additional workspaces that expose various combinations or portions
of 'Cars' and/or 'Aircraft' content.
-->
<dna:workspace jcr:name="workspace">
<dna:projections>
<!-- Project the 'Cars' content, starting with the '/Cars' node. -->
<dna:projection jcr:name="Cars projection" dna:source="Cars" dna:workspaceName="workspace">
<dna:projectionRules>/Vehicles/Cars => /Cars</dna:projectionRules>
</dna:projection>
<dna:projection jcr:name="TempFiles projection" dna:source="FileSystem" dna:workspaceName="/tmp">
<dna:projectionRules>/Vehicles/FileSystem => /</dna:projectionRules>
</dna:projection>
<!-- Project the 'Aicraft' content, starting with the '/Aircraft' node.
-->
<dna:projection jcr:name="Aircarft projection" dna:source="Aircraft" dna:workspaceName="workspace">
<dna:projectionRules>/Vehicles/Aircraft => /Aircraft</dna:projectionRules>
</dna:projection>
<!-- Project the 'System' content. Only needed when this source is accessed through JCR.
-->
<dna:projection jcr:name="System projection" dna:source="System" dna:workspaceName="default">
<dna:projectionRules>/jcr:system => /</dna:projectionRules>
</dna:projection>
</dna:projections>
</dna:workspace>
</dna:workspaces>

<retryLimit>20</retryLimit>

</dna:source>
<!--
A 'System' source needed for the '/jcr:system' branch of the Vehicles source when it is access through JCR.
-->
<dna:source jcr:name="System" dna:classname="org.jboss.dna.graph.connector.inmemory.InMemoryRepositorySource" dna:retryLimit="3" dna:defaultWorkspaceName="default"/>
</dna:sources>

<!--
Define the JCR repositories
-->
<dna:repositories>
<!--
Define a JCR repository that accesses the 'Cars' source directly.
This of course is optional, since we could access the same content through 'vehicles'.
-->
<dna:repository jcr:name="Cars">
<!-- Specify the source that should be used for the repository -->
<dna:source>Cars</dna:source>
<!-- Define the options for the JCR repository, using camelcase version of JcrRepository.Option names
-->
<dna:options jcr:primaryType="dna:options">
<jaasLoginConfigName jcr:primaryType="dna:option" dna:value="dna-jcr"/>
</dna:options>
<!-- Define any custom node types. Importing CND files via JcrConfiguration is equivalent to specifying here.
-->
<dna:nodeTypes jcr:primaryType="dna:nodeTypes"/>
<!-- Define any namespaces for this repository, other than those already defined by JCR or DNA
-->
<namespaces jcr:primaryType="dna:namespaces">
<car jcr:primaryType="dna:namespace" dna:uri="http://jboss.org/dna/examples/cars/1.0"/>
</namespaces>
</dna:repository>
<!--
Define a JCR repository that accesses the 'Aircraft' source directly.
This of course isn't really necessary for this example, since we could access the same content through 'vehicles'.
-->
<dna:repository jcr:name="Aircraft">
<!-- Specify the source that should be used for the repository -->
<dna:source>Aircraft</dna:source>
<!-- Define the options for the JCR repository, using camelcase version of JcrRepository.Option names
-->
<dna:options jcr:primaryType="dna:options">
<jaasLoginConfigName jcr:primaryType="dna:option" dna:value="dna-jcr"/>
</dna:options>
</dna:repository>
<dna:repository jcr:name="Vehicles">
<!-- Specify the source that should be used for the repository -->
<dna:source>Vehicles</dna:source>
<!-- Define the options for the JCR repository, using camelcase version of JcrRepository.Option names
-->
<dna:options jcr:primaryType="dna:options">
<jaasLoginConfigName jcr:primaryType="dna:option" dna:value="dna-jcr"/>
</dna:options>
</dna:repository>

</dna:repositories>
</configuration>

— exception thrown by this test method —

java.lang.NullPointerException
at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:173)
at com.google.common.collect.ReferenceMap$ReferenceStrategy$1.getDummyFor(ReferenceMap.java:475)
at com.google.common.collect.ReferenceMap.get(ReferenceMap.java:168)
at org.jboss.dna.jcr.SessionCache.findJcrNode(SessionCache.java:817)
at org.jboss.dna.jcr.SessionCache.findJcrItem(SessionCache.java:941)
at org.jboss.dna.jcr.AbstractJcrNode.getNode(AbstractJcrNode.java:542)
at org.openspotligth.federation.configuration.DNAConfigFromFileTest.shouldAccessFileSystemByFederatedJcr(DNAConfigFromFileTest.java:116)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.junit.internal.runners.TestMethod.invoke(TestMethod.java:59)
at org.junit.internal.runners.MethodRoadie.runTestMethod(MethodRoadie.java:98)
at org.junit.internal.runners.MethodRoadie$2.run(MethodRoadie.java:79)
at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:87)
at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:77)
at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:42)
at org.junit.internal.runners.JUnit4ClassRunner.invokeTestMethod(JUnit4ClassRunner.java:88)
at org.junit.internal.runners.JUnit4ClassRunner.runMethods(JUnit4ClassRunner.java:51)
at org.junit.internal.runners.JUnit4ClassRunner$1.run(JUnit4ClassRunner.java:44)
at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:27)
at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:37)
at org.junit.internal.runners.JUnit4ClassRunner.run(JUnit4ClassRunner.java:42)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:45)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:460)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:673)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:386)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:196)